Plz answer properly i need mt grades to be up

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

How do you convert 4 mmol of bromobenzene to ml?

Two nails have identical sizes and shapes. in one nail, 20 percent of the domains are lined up. in the other nail, 80 percent of the domains are lined up. which has stronger magnetic force? first answer gets brainliest!